Created: Nov 26, 2019 10:07 PM Tags: Expo, React Native, javascript
Introduction
Do you know the Expo project? Expo is a framework and a platform for universal React applications. It is a set of tools and services built around React Native and native platforms that help you develop, build, deploy, and quickly iterate on iOS, Android, and web apps from the same JavaScript/TypeScript codebase.
Workflows
The two approaches to building applications with Expo tools are called the “managed” and “bare” workflows.
- With the managed workflow you only write JavaScript / TypeScript and Expo tools and services take care of the rest for you.
- In the bare workflow, you have full control over every aspect of the native project, and Expo tools can’t help quite as much.
We won’t tell about the bare workflow at this moment, only a problem with so many people using Expo SDK 33 or later.
Expo ImagePicker - launchImageLibraryAsync
There is the ImagePicker
on the API for display the system UI for choosing an image or video from the phone’s library, but there isn’t a way to allow multiple selections of images, as you can see here. There are some feature requests here:
- https://expo.canny.io/feature-requests/p/allow-choosing-multiple-images-in-imagepicker
- https://expo.canny.io/feature-requests/p/multiple-images-and-cameravideo-access-for-image-picker
The solution with React Hooks
In React Native, you can use the Camera Roll API to get media from the phone’s library, then why not build a hook for that? :]
import { useCallback, useState } from 'react';
import { CameraRoll } from 'react-native';
export default function useCameraRoll({
first = 40,
assetType = 'Photos',
groupTypes = 'All',
}) {
const [photos, setPhotos] = useState([]);
const [after, setAfter] = useState(null);
const [hasNextPage, setHasNextPage] = useState(true);
const getPhotos = useCallback(async () => {
if (!hasNextPage) return;
const { edges, page_info: pageInfo } = await CameraRoll.getPhotos({
first,
assetType,
groupTypes,
...(after && { after }),
});
if (after === pageInfo.end_cursor) return;
const images = edges.map(i => i.node).map(i => i.image);
setPhotos([...photos, ...images]);
setAfter(pageInfo.end_cursor);
setHasNextPage(pageInfo.has_next_page);
}, [after, hasNextPage, photos]);
return [photos, getPhotos];
}
After that, you simply use it like this:
// path to your hooks
import { useCameraRoll } from 'shared/hooks';
// ...
function SomeComponent() {
const [photos, getPhotos] = useCameraRoll({ first: 80 });
// ...
}
You can use getPhotos
in a FlatList onEndReached
props , for instance. Problem solved :]
Top comments (6)
requires eject (bare workflow) to use this solution? as seen in github.com/react-native-community/...
hey,
This post is deprecated, so I'll update asap! thanks for reply
Greetings,
any update to this subject. I am interested in using the workaround to upload images and videos as well!
Regards,
Yeah, I'm planning to update it. Stay alert! : ]
Thanks for your support. I am waiting for you!
Regards,
Hi Maurício R Duarte,
any update? thanks in advance